Add the role property to the message person

Author: Suiram1701

WebUntisAPI.Client/Models/Messages/MessagePerson.cs

@@ -23,6 +23,12 @@ public class MessagePerson
         [JsonProperty("tags")]
         public List<string> Tags { get; set; } = new List<string>();
 
+        /// <summary>
+        /// The role of the person
+        /// </summary>
+        [JsonProperty("role")]
+        public string Role { get; set; }
+
         /// <summary>
         /// The displayed name of the user
         /// </summary>